import json
import os
import sys
from sys import argv


def main():
    if len(argv) < 2:
        sys.exit("-1")
    file = argv[1]
    if not os.path.exists(file):
        sys.exit("-2")
    with open(file) as json_file:
        json_string = json_file.read()
        json_obj = json.loads(json_string)
        name = json_obj['page_data']['part'] + ''
        print(name.replace(" ", "_"))


if __name__ == '__main__':
    main()
